Differencial diagnosis

DIFFERENTIAL DIAGNOSIS

Difference between B. anthracis & Anthracoid organisms in culture

B. anthracis
Anthracoid organisms
Non motile generally motile
Capsulated non capsulated
Grows in long chains Grows in short chains
No turbidity in broth Turbidity in broth
Inverted fir tree in gelatin Atypical or absent
Methylene blue reduced weakly Reduced strongly
Haemolysis weak Strong
Liquefaction of gelatin is slow Rapid
Lecithinase reaction is weak Rapid
Ferments salicin slowly Rapid
Produces toxin, neutralised by B.anthracis antitoxin not neutralized
Pathogenic to g.pigs & mice non pathogenic
Susceptible to gamma phage not susceptible

Difference between B. anthracis & Anthracoid organisms in blood smear stained with Polychrome methylene blue stain

B. anthracis
Anthracoid
Dark pink or Purple coloured capsules No capsule
Organism rod stained blue Organism rod stained blue
Ends truncated Ends bulged and rounded
Single, pair or short chain Usually long chain
Absence of spores Spores may be present

 

Last modified: Monday, 4 June 2012, 4:20 AM